This application relates generally to power distribution systems, and more specifically to overcurrent protection in DC power distribution systems.
In power distribution systems where DC power is distributed to multiple different loads, it is known to use a set of switches/relays in conjunction with a power system controller to control the power flowing to each load. In order to facilitate operation and power distribution to all of the loads, a controller, which is capable of controlling the state of each of the switches/relays in the system, is typically utilized.
Initially, systems designed in this way used mechanical relay switches. However, mechanical relay systems suffered from reliability problems. In order to improve reliability, many applications now use semiconductor switches instead of mechanical relays due to a longer life-span of the semiconductor switches. Use of semiconductor switches has the additional benefit of reducing the size of the circuit as well as reducing the weight.
Use of semiconductor switches necessitates a different style of controller than the controller used for mechanical relay switches. Existing semiconductor switch controllers are expensive to construct and maintain, are larger than desirable for use in many systems, such as aircraft power systems, and do not readily scale for different sized loads and trip currents.